blupdf vs Sejda

No. Sejda's editor page states that editing scanned documents is not supported and that changing existing text within scanned documents is not supported. blupdf recognises the text on a scanned page, rebuilds the page as real text in matched fonts, and lets you retype any line or hand the change to blupdf AI, then download a searchable PDF.

Sejda is free for documents up to 200 pages or 50 MB with 3 tasks per hour, with paid passes and subscriptions beyond that. blupdf gives every account 1,000 credits with no card and no expiry; downloads, signatures and pages are free, so the credits go to the work itself: 50 per digital page, 80 per scanned page, 1 per character of new text.

Both reuse embedded fonts. When characters are missing, Sejda asks you to choose a replacement; blupdf picks the closest of its 35 library families automatically by category, weight, width and x-height, and lets you override it. On scans, only blupdf renders edits in a matched font, because only blupdf edits scans.

Its editor page does not document AI editing. In blupdf, Ask AI opens blupdf AI: describe the change in plain language, and the edits land in the original font everywhere the text occurs, with dependent totals recomputed and number styles kept. Each request costs 100 credits plus the characters written.